In the case of valves for hydraulic applications, various types of actuation have been developed over time, ranging from a purely manual control with a manual lever to direct electromagnetic control or hydraulic pilot control to highly dynamic servo drives. As a further type of valve actuation, electromechanical control by a step motor has recently been added in the prior art. U.S. Pat. No. 7,591,448 B2 discloses a solution to this effect for a valve of the type mentioned at the outset. Such solutions are increasingly being used for mobile applications such as construction machines, agricultural machines, forklifts, cranes or other machines.
However, these solutions do not always meet the requirements in terms of safety, because, in the event of a step motor failure or a failure of the electrical system, the valve is returned to a safe neutral position. There is the risk that the related machine then cannot be brought into a safe state and remains in a state endangering the environment.